Chapter 7 Endomembrane system, Protein Sorting and membrane trafficing Learning obiective 1. Compartmentalization in Eukaryotic Cells 2. The structural and functional relationship between the ER, Golgi complexes, lysosomes and plasma membranes of eukaryotic cells 3. The pathways of proteins targeting and sorting, and its mechanisms 4. The ways of protein modifications and intracellular sites after they are synthesized; 5. Types of vesicle transport and their functions
Chapter 7 Endomembrane system, Protein Sorting and membrane trafficing Learning objective 1. Compartmentalization in Eukaryotic Cells; 2. The structural and functional relationship between the ER, Golgi complexes, lysosomes and plasma membranes of eukaryotic cells; 3. The pathways of proteins targeting and sorting, and its mechanisms; 4. The ways of protein modifications and intracellular sites after they are synthesized; 5. Types of vesicle transport and their functions
1. The Compartmentalization in Eukaryotic Cells Membranes divide the cytoplasm of eukaryotic cells into distinct compartments Tree categories in eukaryotic cells: )the endomembrane system: ER, Golgi complex, Lys secretory vesicles (2)the cytosol (3)mitochondria, chloroplasts, peroxisomes, and the nucleus Membrane-bound structures (organelles)are found in all eukaryotic cells
1. The Compartmentalization in Eukaryotic Cells vMembranes divide the cytoplasm of eukaryotic cells into distinct compartments. Tree categories in eukaryotic cells: (1) the endomembrane system: ER, Golgi complex, Lys., secretory vesicles. (2) the cytosol. (3) mitochondria, chloroplasts, peroxisomes, and the nucleus. vMembrane-bound structures (organelles) are found in all eukaryotic cells
A Cytosol and its functions >Cytosol: The region of fluid content of the cytoplasm outside of the membranous organelles. Aqueous solution of large and small molecules including filaments of cytoskeleton which act as organizer for some order >The cytosol is the site of protein synthesis and degradation or modification. It also performs most of the cell,s intermediary metabolism
ØCytosol: The region of fluid content of the cytoplasm outside of the membranous organelles. Aqueous solution of large and small molecules including filaments of cytoskeleton which act as organizer for some order. ØThe Cytosol is the site of protein synthesis and degradation or modification. It also performs most of the cell’s intermediary metabolism. A. Cytosol and its functions
B Endomembrane system x Endomembrane System The structural and functional elationship organelles including Er, Golgi complex, ysosome, endosomes, secretory vesicles. Membrane-bound structures (organelles) are found in all eukaryotic cells Endocytic Perinuclear space envelope
B. Endomembrane System vEndomembrane System : The structural and functional relationship organelles including ER,Golgi complex, lysosome, endosomes, secretory vesicles. vMembrane-bound structures (organelles) are found in all eukaryotic cells
rough endoplasmic reticulum nucleus lysosomes 来A|rcaL 5 um peroxisome mitochondrion
Relative volumes occupied by the major intracellular compartments in Liver Cell Intracellular compartment o of total cell volume Cytosol 54 Mitochondria 22 Rough er cisternae Smooth er cisternae plus Golgi cisternae 966 Nucleus Peroxisome lysosomes Endosomes
Intracellular compartment % of total cell volume Cytosol 54 Mittchondria 22 Rough ER cisternae 9 Smooth ER cisternae plus Golgi cisternae 6 Nucleus 6 Peroxisome 1 Lysosomes 1 Endosomes 1 Relative volumes occupied by the major intracellular compartments in Liver Cell
C. The Dynamic Nature of the Endomembrane system Most organelles are part of a dynamic system in which vesicles move between compartments o Biosynthetic pathways move proteins, carbohydrates and lipids within the cell Secretary pathways discharge proteins from cells Endocytic pathways move materials into cells Sorting signals are recognized by y receptors and target proteins to specific sites
C. The Dynamic Nature of the Endomembrane System vMost organelles are part of a dynamic system in which vesicles move between compartments. vBiosynthetic pathways move proteins, carbohydrates and lipids within the cell. vSecretary pathways discharge proteins from cells. vEndocytic pathways move materials into cells. vSorting signals are recognized by receptors and target proteins to specific sites
A few approaches to the study of cytomembranes Insights gained from autoradiography; Insights gained from the biochemical analysis of subcellular fractions Insights gained from the study of genetic mutants; The dynamic activities of endomembrane systems are highly conserved despite the structural diversity of different cell types
D. A few approaches to the study of cytomembranes v Insights gained from autoradiography; v Insights gained from the biochemical analysis of subcellular fractions; vInsights gained from the study of genetic mutants; The dynamic activities of endomembrane systems are highly conserved despite the structural diversity of different cell types
De duve. A Claude and G Palade. 1974 Nobel prize Golgi vesicles Secret Time of chase (min) Lumen Golgi comple Endoplasmic reticulum Mitochondna 20 min 120 min
De Duve, A.Claude and G.Palade,1974 Nobel Plrize
2. The structure and functions of Endoplasmic Reticulum(ER) inner nuclear membrane ER membrane nucleus outer nuclear membrane polyribosome RER has ba ribosomes on the cvtosolIc de of continuous flattened sacs (cisternae): A) 200nm 400nm SER IS an 5(B) rough ER smooth印R Interconne cting network of tubular membrane elements o0 nm ER lumen
2. The structure and functions of Endoplasmic Reticulum(ER)
